Automatic image processing techniques have been widely applied in various industries, from automatic reading and tracking of bar codes in a production line, automatic recognition of an vehicle license plate, automatic defect detection of components, DVD recognition and automatic return, to directing a robot hand to assemble apparatus and the like, in which the image processing techniques play an important role. As the image processing techniques are highly intelligent and stable, and have good repeatability and high precision, they can be used to replace human to do intensive repetitive work. Because of such features, the image processing techniques have been introduced into the field of communication and to photoelectric products. Communication products include many photoelectric products that in common utilize conversion of light to electricity or electricity to light, most of which need lenses to focus light beams. In such products, it is important to ensure alignment between centers of the lens and the PD or laser.
In a patent application No. 201310433022.2 entitled “optical waveguide chip and PD array lens coupling device”, a lens array is used in a coupling structure of the waveguide chip and the PD array. This patent uses a die bonder to achieve alignment of the lens array and the PD array. In the bonding operation, the operator determines whether the lens array center and the PD array photosensitive area center are coincided with each other by his/her eyes. This method may have large artificial error in deciding centers of the lens array and the PD array, and have poor repeatability. And, if a high speed PD array is used which has a photosensitive area of only several tens of micrometers, error in determining alignment of centers would be larger. In addition, the die bonder of high precision is expensive, and maintenance cost thereof is also very high.